Multilayer print film having incorporated coloring material



Dec. 14, 1954 E. E. JELLEY ET AL MULTILAYER PRINT FILM HAVING INCORPORATED COLORING MATERIAL Filed Nov. 25, 1949 Fig. 1.

Red sensitive AQ Green sensitive AgCI Containing blue dye Blue sensitive A9 Green sensitive Agcl Red sensitive AgCl Blue interla yer Blue sensitive Ag 5r" Edwin E. Jelley Arthur H. Her-z (Ittornegs United States Patent 9 MULTILAYER PR NT. HAVING INCORPO- R D. c mma MATERIAL This invention relates to photography and particularly to a inillti-layerphotographicfilm having alight filtering material incorporated therein In the usual sensitivity arrangement of. three-layer photographic film, the" red-sensitive, emulsion layer" is coated adjacent the support and, this followed in order by the green-sensitive emulsion layer and the blue-sensitive emulsion layer, It is customary. to form a cyan dye ma e v the te en it v ater; ma enta dye m i th reenn v ayer and a ello dye image the blue-sensitive layer. It is well known. that the definition oft-he resulting color. picture is determined to a large extent by the cyan and magenta dyes and that the overall definition can be improved by, arranging the three emulsion layers so that the layer containing the cyan or maaent ye is outerm t and h lay contain e, Yellow dye is adjacent the support or farthest from the exposing light. This arrangement is described, for example, in Baker U. S. Patent 1,867,301 and. Tarbin U. S.' Patent 1,871,479.

When this inverted, sensitivity order is used, it is frequently'necessary to employ a blue-sensitive emulsion layer, that is, the layer'adjacent the support, having a higher blue light'speed than would be required if the blue-sensitive layer were outermost. 'Whether for this or other reasons,'it has been found that the blue-sensitive emulsion layer tends to scatter any red or green light reaching it after passing through the upper layers and therebytore'ducethe overall definition of the resulting. picture; This light scatteringin the bottom layer of the film cancels'out the advantages obtained by placing the green-sensitive or red-sensitive layer outermost and is a serious defect" in films using this sensitivity arrangement.

It is therefore an obiect of. the present invention to retain the advantagesof'coating the green-sensitive or red-sensitive layer outermostv in a multi-layer film and at the same time to reduce or overcome the disadvantage of light scatter Gail'sedhythe blue-sensitive emulsion layer. A further object is to provide anovel multi-layer photographic ,1 t 8 These obiects are accomplished by coating the bluesensitiv'e layer adjacent the support and including in one of 'the'lavers over the blue-sensitive layer a dye or pigment which absorbs light to which one'or both of the upper layers are sensitive, particularly a dye or pigment having a transmission in the visible spectral region'for blue light only.

The accompanying drawing shows in sectional view films constructed according to our invention.

The film used according to our invention consists of a suitable support such as cellulose ester, svnthetic resin or paper having on one side thereof. suitable subbing layers and a blue-sensitive silver halide emulsi n layer coated thereon. This is followed bv green-sensitive and red-sensitive silver halide emulsion lavers either of which may be outermost, although we prefer to coat the greensensitive emulsion layer last or outermost. Since the green-sensitive and red-sensitive silver halide emulsions are sensitive to blue or violet light in addition to the regions to which they are optically sensitized, it is necessary to prevent the action of blue or violet light on these layers. This may be accomplished either by using as the bottom layer a blue-sensitive emulsion which has much higher blue speed than the green-sensitive and red-sensitive emulsions and exposing the entire film through a yellow filter which absorbs all blue light to which the upper 2v layers are sensitive but not all, blue light to which the bottom layer is sensitive, or by using inthe upperlsygrs emulsions consisting principally of silver ch d has very little sensltivity in" the visible'blu h The ls o av fs iiav. bnt h d iul rsird described in 1611" y 'andfXjittum U'."S,. rarenrznzznzjg According to the preferred bodim nt of our invention, the blue-sensitivelayer is a silverb'r'o chlorobromide emulsion"S S tive to'visible blue light and containing a 'couplefcapable of. forming a yello'vv dye image. The red-sensitive and"green-sensitive emulsions are silver chloride or'silv'er chlorobromide emulsions rela tively insensitive tofvisiblei bl'lie' liglitfafid cijntaining, r spectively', couplers capable of produc ng cyan and niagenta i v, M ...i in.

A dye 'or pigment which absorbs red. or green light or both is incorporated'in at las' one of the l jyers. over the bl e-. n iti mul a i- T 1 151 h 13 ,g ment is blue, cysnflstsgemserree "nd is incorporated, in thered-sens itive' 6r green-sensitive lays-test both or in an inter-layer between theselayers and the, blnef-sensi tive layer or acon bination'of.both.

A suitable bluejtransmitting pigment for this purpose is Prussian Blue' or oneflif'the related. ferric-ferrocyanides. The rollow ns e'x mii d s' h i'fl pr i a s ln d it r'r laye'rsand emulsions containing Prussiarmue:

Turnbulls Blue in gelatin was prep'ared by adding si. multaneously, to 180. cc. of a solution'of gelatin water containing 4.0] g ms of gelatinper 1,00 cc. of water at pH 2.5 to 3.0, 'asolutiouof 3,.6. grams of ferrous am; monium sulfate in 36' cc. of waite' antla solution of. 3.0 grams of potassium ferricyanid e' 1113 .6 cc. or. water at 40 C. The solutions were run in slowly over a period of three minutes with continuous mechanical stirring. The dispersion was chilled' r' itil the gelatin entirely set, then chilled and, washed inruii g'wate'r'fo'r/thr'ee' hours to remove soluble by-products and excess potassium ferricyanide. This method of preci 'tation gives" a better dispersion than addine thefull amount of either ofthe salts to the gelatin before the. other, and the excess ferri cyanide is washed out of the gelatin: more readily than excess ferrous salt. Precipitation of a ferric salt bv'ferro van e mav a so. be. u e under. im lar si t nns :1 h j we have d. e s er to secure: a oo di peri 9 TF qu e meter ha a opti al; denser o -Q a 69 ,m "1 "rfi$ This ives adequate protection against; Y tered light.

During the color processing of a multi-layer film having Prussian Blue incorporated in an interlaver or in an emulsion l yer or both. the Prussian Blue is ble ched in the stron lv alkaline devel ner'with the forma i n of. ferric hvdroxide and a soluble fermcvanide. 'These products: are known to be the same hether th precipit te is f rmed from a ferric salt and ferrocvanide or from a ferrous salt and ferricvanide. If the film; is, washed after develop; ment. the ferroc'vanide will be removed,- and a subseauent acid bath will dissolve the ferric hydroxide. IfJhowever. the film goes directlv from the develo er into an acid stop bath or fixing bath, there is danger that some Prussian Blue mav be reformed. This may be prevented by incorporating in the developer, materials forming complex ions with ferric ion such as citrates, tartrates, oxalates, fluorides or ethylene diamine tetraacetic acid. In practice, this has not been found necessary when using an acid dichromate bleach and removal of silver after color developement but if a ferri-cyanide bleach were employed,

precautions for removal of the ferric salts would be necessary.

Besides Prussian Blue, the following dyes and pigments may be used:

1. 2,3,2,3'-tetraphenyl-1,l pyrrocolinocarbocyanine bromide. This dye is described in Sprague U. S. patent application Serial No. 18,863, filed April 3, 1948. It is a red absorbing dye, bleaching in developers containing moderate amounts of sulfite and should be employed as an interlayer rather than in emulsion. As an interlayer it may be employed either as a dispersion prepared by adding a methanol solution of the dye to gelatin or by adding it to a very fine grained silver bromoiodide emulsion to reduce diffusion. The optical density at 690 mu Wlll be approximately 0.3 for 20 mg. of dye per square meter.

2. in camera films where bleaching of the filter layer is not essential, it is possible to use a dispersion of copper phthalocyanine in gelatin, for example the material sold by Du Pont as Monastral Blue GSWD. This is completely free from desensitization or diffusion.

3. Bis[l,3-diethyl-Z-thiobarbituric acid pentamethineoxonol may be used as a red absorber. For example, to 454 g. of gelatin made up as a solution, there is added 12 g. of bisll,3-diethyl-2-thiobarbituric acid-(5) l-pentamethineoxonol dissolved in 50 cc. pyridine and 1500 cc. methanol. Then 48 g. of polyvinyl pyridine metho-p-toluene-sulfonate dissolved in water are added. Coating at mg. of dye per square meter, the optical density will be approximately 0.3 at the maximum. The dye is described in Gaspar U. S. Patent 2,274,782 and the polyvinyl pyridine mordant in Sprague and Brooker U. S. patent 6application Serial No. 719,623, filed December 31, 194

4. To 454 g. of gelatin as a 10% solution, there are added 3 g. of 4[(3-ethyl-2(3)-benzoxazolylidene)butenylidene]-3-niethyl-l-p-sulfophenyl 5 pyrazolone dissolved in 200 cc. methanol, 2.5 cc. pyridine and 200 cc. water; then 8 g. of polyvinyl pyridine metho-p-toluenesulfonate in 800 cc. of water. Coating at 30 mg. of dye per square meter, the optical density at 550 m would be approximately 0.3. This dye is prepared in the manner described in Brooker and White U. S. patent application Serial No. 605,472, filed July 16, 1945.

In addition to blue dye or pigment, the film may con tain a magenta or reddish dye or pigment. For example, the aluminum lake of aurin tricarboxylic acid may be incorporated in the layer containing the blue dye or pigment, or in a separate layer.

Our invention will now be described by reference to the accompanying drawing. As shown in Fig. 1 thereof, 10 is a support having thereon a blue-sensitive silver bromide emulsion layer 11, a green-sensitive silver chloride emulsion layer 12 containing a blue dye, and a red-sew sitive silver chloride emulsion layer 13.

Fig. 2 illustrates a modification of our invention in which neither the green-sensitive silver chloride emulsion layer 13 nor the red-sensitive silver chloride emulsion layer 14 contains a dye or pigment but a blue pigment is contained in the interlayer 15 between the blue-sensitive emulsion layer Ill and the red-sensitive emulsion layer 14.

It will be understood that the modifications and examples included herein are illustrative only and that our invention is to be taken as limited only by the scope of the appended claims.

We claim:

1. A multi-layer photographic element capable of producing colored images having improved definition, comprising a single support having on one side thereof three, integrally united. silver halide emulsion layers separately sensitive to the blue, green and red spectral regions, said blue-sensitive emulsion layer being adjacent said support and having a much higher blue speed than said greensensitive and red-sensitive emulsions, and in a layer between said blue-sensitive emulsion layer and the layer prising a farthest from said support, a non-image-forming coloring material absorbing a major amount of red light and a minor amount of green light and transmitting substantially all blue light, said layers being otherwise uncolored with an image-forming coloring material.

2. A multi-layer photographic element capable of producing colored images having improved definition, comprising a support having on one side thereof three silver halide emulsion layers sensitive in order to the blue, red and green spectral regions, said blue-sensitive emulsion layer being adjacent said support and an insensitive interlayer between said blue-sensitive emulsion layer and said red-sensitive emulsion layer containing a blue coloring material absorbing a major amount of red light and a minor amount of green light and transmitting substantially all blue light.

3. A multi-layer photographic element capable of producing colored images having improved definition, comprising a support having on one side thereof three silver halide emulsion layers sensitive in order to the blue, red and green spectral regions, said blue-sensitive emulsion layer being adjacent said support, and an insensitive interlayer between said blue-sensitive emulsion layer and said red-sensitive emulsion layer containing Prussian Blue pigment.

4. A multi-layer photographic element capable of producing colored images having improved definition, comsupport having on one side thereof three silver halide emulsion layers sensitive in order to the blue, red and green spectral regions, said blue-sensitive emulsion layer being adjacent said support, said red-sensitive emulsion layer containing a blue coloring material absorbing a major amount of red light and a minor amount of green light and transmitting substantially all blue light, said layers being otherwise uncolored with an image-forming coloring material.

5. A multi-layer photographic element capable of producing colored images having improved definition, comprising a support having on one side thereof three silver halide emulsion layers sensitive in order to the blue, red and green spectral regions, said blue-sensitive emulsion layer being adjacent said support, said red-sensitive emulsion layer containing Prussian Blue pigment, said layers being otherwise uncolored with an image-forming coloring material.

6. A multi-layer photographic element capable of producing colored images having improved definition, comprising a support having on one side thereof three silver halide emulsion layers sensitive in order to the blue, red and green spectral regions, said blue-sensitive emulsion layer being adjacent said support, and in at least a layer over said blue-sensitive emulsion layer a non-image-forming Prussian Blue pigment, said layers being otherwise uncolored with an image-forming coloring material.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 927,244 Ives July 6, 1909 1,173,429 Ives Feb. 29, 1916 1,306,904 Ives June 17, 1919 1,447,759 Christensen Mar. 6, 1923 2,344,084 Gaspar Mar. 14, 1944 

1. A MULTI-LAYER PHOTOGRAPHIC ELEMENT CAPBLE OF PRODUCING COLORED IMAGES HAVING IMPROVED DEFINITION, COMPRISING A SINGLE SUPPORT HAVING ON ONE SIDE THEREOF THREE, INTEGRALLY UNITED, SILVER HALIDE EMULSION LAYERS SEPARATELY SENSITIVE TO THE BLUE, GREEN AND RED SPECTRAL REGIONS, SAID BLUE-SENSITIVE EMULSION LAYER BEING ADJACENT SAID SUPPORT AND HAVING A MUCH HIGHER SPEED THAN SAID GREENSENSITIVE AND RED-SENSITIVE EMULSIONS, AND IN A LAYER BETWEEN SAID BLUE-SENSITIVE EMULSION LAYER AND THE LAYER FARTHEST FROM SAID SUPPORT, A NON-IMAGE-FORMING COLORING MATERIAL ABSORBING A MAJOR AMOUNT OF RED LIGHT AND A MINOR AMOUNT OF GREEN LIGHT AND TRANSMITTING SUBSTANTIALLY ALL BLUE LIGHT, SAID LAYERS BEING OTHERWISE UNCOLORED WITH AN IMAGE-FORMING COLORING MATERIAL. 